What Happened To The Native Species?

The early history of fishery management within national parks, involved the frequent transplant and stocking of fish to enhance recreational fishing. Knowledge of the extent of potential ecosystem impacts of this kind of management activity was lacking in those early days. Stocking was thought to be a good way to improve recreational fishing opportunities. Often new species were brought into an area and introduced into lakes or streams with hopes of increasing the number and diversity of fish available. Fish were also stocked into high alpine lakes and other locations where they had not occurred historically. As our scientific understanding and knowledge of natural ecosystems has progressed, managers of protected natural areas have come to realize that the introduction of fish species that are not native to the area results in harmful impacts to the natural ecology of the aquatic system. Native species are often out competed by the introduced fish species and become greatly reduced in number or even lost from the system completely. Food organisms may be over consumed and the natural balance of other aquatic organisms present will likely be changed.

Today the National Park Service no longer stocks fish in natural areas but instead relies on natural reproduction and careful management of fishing activities to sustain fish populations and fishing opportunities. However, early stocking practices have left the parks with many areas in which non-native fish continue to dominate and displace the native species. Elimination of these non-native species is not possible in many cases, but where possible, the NPS is working to remove the non-native species and reintroduce or restore the native species to help reestablished the natural aquatic ecosystem. Restoration is usually accomplished through electro fishing and chemical treatment of stream sections above natural fish barriers (such as waterfalls) to remove all non-native fish, then native species are reintroduced from other surviving populations. The Water Resources Division is providing technical assistance for native fish restoration projects at several National Parks and will continue to do so over the next several decades. Nearly every national park with fishery resources has been impacted by the introduction or invasion of non-native species. Visitors can help restore native fish by releasing all native fish that they catch and keeping all non-native fish caught.

Native Fish - A fish of a species that occurred within that river, stream or lake historically and was not introduced into that water body by man.

Non-Native Fish - Any fish species that did not historically occur within that river, stream or lake and was introduced by man into that water body.

Both native and non-native fish may be reproducing naturally within the river, stream or lake and have self-sustaining populations.

Why Promote Just Native Species?

National Parks and the National Park System have been established by Congress to preserve and protect designated outstanding examples of our nation's most prized natural and cultural resources. That mission requires that the National Park Service manage those areas under its stewardship in a way that provides protection to the native species and natural ecosystem processes, and in a way that insures these resources will remain unimpaired for present and future generations. Opportunities abound outside of the national parks to fish for non-native species or for fish in populations whose numbers have been artificially enhanced through stocking programs. The National Park Service is therefore dedicated to promoting the opportunity for fishermen to fish for wild native species in their natural environment.